Fuel control means



2. Sheets-Sheet 1 IllllllllillIIIIIIBIEIIIlIjIH M. E. CHANDLER lUELCONTROL MEANS Ur-iginal Filed Feb. 1, 1937 l. l k.

Jan; 26, .1943.

Jan. Z6, 1943. M. E. CHANDLER Re 22,254

' I FUEL CONTROL MEANS original Filed Feb. '1-, 1957' 2 shets-sheet 2Ressued Jan. 26, 1943 FUEL CONTROLMEANS Milton E. Chandler, Birmingham,Mich., assignor, by mesue assignm Corporation, Meriden,

Delaware ents, to Chandler-Evans Conn., a corporation of riginal No.2,125,886, dated August 9, 1938, Serial .Nm 123,359, February 1, 1937.

Application for reissue April 13, 1939, Serial No. 267,730

12 Claims.

This invention is an improvement on the carburetor shown in the MiltonJ. Kittler Patent No. 2,232,392 issued Feb. 18, 1941. In a carburetor ofthis type it is desirable that the mixture ratio be richer at maximumpower than it is under throttle, because the engines to which thesecarburetors are applied are built so closely to their safety limit thatunless excess fuel is used, the engines fail because under the excessiveheat the strength of the parts subjected to the heat is reduced.

As pointed out in the above case, the mixture ratio does not varyappreciably with altitude.

. Hence the applicant has discovered that if he utilizes the rate offlow of fuel to the carburetor he carl control the additional fuel by adevice controlled by this iiow and thereby obtain a definite percentageincrease in the mixture ratio. In other words, if the mixture ratio iscorrect, that is to say, gives a uniform mixture regardless of throttleposition or altitude, then a definite deviation from this theoreticalmixture for practical purposes can also be controlled by the flow andthe percentage increase will be uniform regardless of variations inaltitude.

In the drawings:

Figure 1 shows a cross sectional elevation taken on plane l-l-Iof Figure2.

Figure 2 shows a cross sectional elevation taken on. plane 2 2 of Figure1.

Figure 3 shows a modification of the novel control means.

Figure 4 shows another modification of the control means.

In the drawings the fuel supply is connected to anengine driven pump Hdelivering fuel under a considerable pressure (from 4 to '1 pounds persquare inch) controlled by a Sylphon bellows W. B is the fuel entrancechamber in which islocated the flexible metal bellows C supported by ahelical spring D. This spring is mounted on the cover E which engageswith the body F of the control device. A passage G in the body Fconnects the interior of the bellows C with the throat of a venturi J.This throat is sumciently restricted so that a definite number of inchesof mercury depression is created and transmitted through the pipe G tothe interior of the bellows C. -The restriction, however, is notsufficient to create an appreciable resistance to the iiow of gasolinethrough J. The gasoline flows through J to the pressure reduction valveL to the diaphragm chamber M through which it discharges under aconstant head of relatively low value into the passage N, the flowthrough which is cons trolled by the needle valve U which is moved inunison with the throttle valves V, V. The corrugated bellows C carries aneedle valve P which serves to cut oi the connection between the fuelchamber B and a fuel passage Q and also to regulate the flowtherethrough. This passage Q com municates with an air passage R whichis connected tothe air entrance S. A fuel passage T in the nozzle bar Oserves as the fuel outlet from the passage Q into the mixing chamberbetween the throttles V, V. The mixture of fuel and air controlled bythe needle valve U discharges through the opening X into the mixingchamber. When the throttle is closed, a little air is admitted throughthe annulus A which derives its air from the air entrance S through thecenter of the hollow needle U. An air vent AI is provided .in the nozzlebar O.

A chamber Y is located at one side of the diaphragm MI and communicatesthrough the pipe K with the mixture chamber through a passage A2 in theinterior of the nozzle bar O.

A valve Z controls the connection between the chamber Y and the openingsX so as to modify the pressure in the diaphragm chamber by the nozzle4suction. The chamber Y is also connected through the tube I with the airentrance S. The valve Z is so designed that the chamber Y cancommunicate with the air entrance S through the pipe I or with themixing chamber through the openings X, X or with both the air entrance Sand with the nozzle suction at X. The opening of the needle valve U iscontrolled by the movement of the throttles V, V through vthe linkageVl, V2.

operation The operation of the engine proceeds in a normal way until theflow through the venturi J reaches a predetermined valu'e at which timethev depression therein is suflicient to overcome the spring D and theneedle valve P is opened. When the needle valve P opens, fuel flows fromthe fuel regulating chamber W to the passage Q under the pressure offuel in the fuel pump H. Additional fuel is therefore discharged throughT into the mixing chamber. As the pressure in chamber W runs from fourto seven pounds per square inch, the flow through T is determined by thepressure in chamber W and the opening around the needle valve P ratherthan bythe ilow of air from the air entrance S through thel passage Rinto thel fuel outlet T. In other words, the additional fuel admitted.at T is directly controlled solely by the quantity of fuel flowingthrough the venturi J and the absolute pressure of the fuel from thefuel pump, but, indirectly, as is obvious, by the air flow through theair entrance passage S. The result is that when the' engine is opened upand the horsepower developed reaches a critical value, a definite amountof excess fuel is admittedthrough the opening T and lthe tendency of theengine to burn up is counteracted by the cooling effect of theadditional fuel 'admitted through the opening T, which` addition isproportional to the normal flow. By making the mixture excessively rich,it is possible to develop an extra in power. The extra fuel produces alower engine temperature and thus prevents the engine overheating.

In Figure 3 the spring D is supported by a lSylphon bellows DI so thatas the altitude increases the spring D becomes compressed and4 hence theopening of the needle valve P is reduced.

In Figure 4 a sharp edged orifice J' is substituted for the venturi J.

engine in quantities bearing a substantially constant ratio toquantities of air flowing through The diaphragm chamber M is shownlocated so that its center is higher than the passage N.Y In the Kittlerpatent referred to above, it has been found advantageous to locate thepassage N above the chamber M, but the drawings in this case were madediagrammatic to illustrate the featurer shown bythe parts B, C, D, E, F,G, J, and P.'

and this device is not restricted to carburetors in which the mixtureratio remains substantially constant at altitudes.

What I claim is:

1. In a carburetor having a source of fuel supply under substantiallyconstant pressure, a fuel fuel supply directly to the carburetor, asecond fuel valve in said second passage, and means responsive to theflow of gasoline from the high pressure fuel inlet to the pressurereducing valve for operating said second valve f or the purposedescribed.

2. In an internal combustion engine, the combination with a throttlecontrolled air inlet, of two fuel nozzles having restricted orificesarranged to discharge into said inlet adjacent to said' throttle, amechanically operated fuel pump for, supplying liquid fuel to saidnozzles, means controlled by the throttle for varying the area of thedischarge orifice of one of said nozzles, and means actuated by the rateof flow through said one nozzle orifice for controlling the area of theother orifice.

' 3. Fuel control means comprising a source of fuel under asubstantially constant pressure, a fuel passage leading therefrom to anengine intake conduit, a Venturi-shaped restriction in said passage, asecond passage leading to said conduit, a regulating valve in saidsecond passage, a chamber having a flexible wall exposed on one side tothe fuel pressure in the first passage, a passage for exposing the otherside of the flexible wall to the pressure existing in the throat of saidventuri, a connection from said flexible wall to said valve, andyieldable means for closing said valve in opposition to the suctioncreated in the throat of said venturi.

4. In an internal combustionengine fuelsystem, means providing a.passage for supplying air 'to the engine, means for supplying fuel tosaid saidpassage per unit of time and over a substantial range ofvariation in quantities of air per unit of time, auxiliary fuel supplymeans including a valve operative to supply additional quantities offuel to said engine over a portion of said range and in substantiallypredetermined ratio to quantities of air flowing through said passageper unit of time over said range portion, and means responsive tovariations in atmospheric conditions and operatively associated withsaid valve to control the fuel suppleciby said auxilliary supply meansfor varying the ratio of fuel to air over said range portion.

'5. In an internal combustion engine fuel system, means providing apassage supplying air to the` engine, means for supplyingfuel to saidengine in quantities bearing a substantially constant ratio toquantities of air flowing through said passage per unit of time and overa substantial range of variation in quantities of air per unit of. time,auxiliary fuel supply means operative to supply additional quantities offuel to said engine over a portion of said range and in substantiallypredetermined ratio to quantities of fuel flowing through the first saidfuel supply means per unit of time over said range portion, and meansresponsive to variations in atmospheric conditions for modifying theoperation of said auxiliary fuel supply means to vary the quantity offuel supplied thereby.

6. In a fuel supply system, means providing an engine air intake passagefor the supply of air and fuel andy including a Venturi-shaped portion,a fuel conduit for supplying fuel from a fuel source to said passage,said fuel conduit including a Venturi-shaped portion for the flow offuel only therethrough, `means providing a second conduit for supplyingfuel from said source to said passage, a valve for controlling flow offuel through said second conduit, means responsive to the .pressure dropat the throat of the vVenturishaped portion of said air passage forcontrolling the flow of fuel through the first said conduit inpredetermined ratio to air flow through said passage, and meansresponsive to the pressure drop at the throat of the Venturi-shapedportion of the first said conduit for operating said valve forcontrolling the flow of fuel through the second said conduit.

7. In a device of the character described, the combination with athrottle controlled air inlet,

of two fuel nozzles having restricted orifices artially constantpressure, a fuel passage leading from said source to said deliveryconduit, a second fuel passage also leading to said delivery conduit, arestriction in the rst mentioned passage, a regulating valve in thesecond passage, and means responsive to the-drop in pressure created bysaid restriction for opening said valve for the purpose described. f

9. In a carburetohaving a mixture chamber of Venturi form, a fuel nozzledischarging there-l in, a sJurce of fuel supply connected thereto andunder a substantially'constant pressure substantially greater thanatmospheric pressure, a second fuel nozzle discharging into the mixturechamber, a valve controlling the flow to said second nozzle and normallyclosed under a relatively low rate of fuel flow to the first saidnozzle, and'means responsive to a predetermined increase in the fuelflow rate to the first nozzle for opening said valve.

10. In a Vfuel supply system, means providing an air passage, a fuelnozzle discharging into said passage, a source of fuel supply connectedthereto, and under a substantially constant pressure substantiallygreater than atmosplf'lxric pressure, a. second fuel nozzle discharginginto said passage, a valve controlling the flow to said second nozzleand normally closed under a relatively low rate of' fuel flow to the rstsaid noz. zle, and means responsive to a predetermined increase in thefuel flow rate to the first nozzle for openingsaid valve.

l1. In an internal combustion engine fuel supply system, means providinga passage for the flow of air to be mixed with fuel and supplied to theengine, means for supplying fuel into said passage in substantiallyconstant ratio to the air flowing through said passage throughout asubstantial range of variation of such air flow per unit of time, andmeans mechanically independent of the first said supply means forsupplying additional fuel to said engine over a part of said range ofair ow variation in quantities substantially proportionate to thequantities of fuel supplied by the first said 4fuel supply means throughsaid part of said range of air now varia tion.

12. In an internal combustion engine fuel supply system, means providinga passage for the flowof air for combustion in the engine, means forsupplying fuel to the engine in predetermined unit quantity per unitquantity of air flowing through said passage to the engine throughout asubstantial range of variation of such air flow per unit of time, andmeans mechanically independent of the first said supply means and con--Mrm'oN E. CHANDLER.

